"This is the first study that took a group of people with documented personality characteristics but no symptoms of Parkinson's disease and showed that those with high levels of an anxious or pessimistic personality are at higher risk for developing Parkinson's disease up to several decades later," says James Bower, M.D., Mayo Clinic neurologist and the study's lead investigator.
Although the study demonstrates an association between anxious and pessimistic personality types and Parkinson's, the findings do not provide the exact reason for these links; this will be the subject of further study by the investigators.
"What we have shown in this study is that there's a link between an anxious or pessimistic personality and the future development of Parkinson's," says Dr. Bower. "What we didn't find is the explanation for that link. It remains unclear whether anxiety and pessimism are risk factors for Parkinson's disease, or linked to Parkinson's disease via common risk factors or a common genetic predisposition."
Though the findings demonstrated a higher degree of risk for Parkinson's later in life for those with anxious and pessimistic personality types, the investigators did not find a huge increase in risk.
"We found a significant and definite link between anxious and pessimistic personalities and the future development of Parkinson's disease," says Dr. Bower. "But, the increased risk was relatively small. Just to give you an idea of numbers, if you take 1,000 40-year-olds, about 17 of them will eventually develop Parkinson's disease. If you take 1,000 anxious 40-year-olds, about 27 of them will develop Parkinson's disease.
Contact: Lisa Lucier